package arrays_string;

public class AllUnique {
	
	public static void main(String[] args)
	{
		String s = "abcdefgh";
		
		for(int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);
			for(int j = i+1; j < s.length(); j++) {
				if(c == s.charAt(j)) {
					System.out.println("YES");
					return;
				}
			}
		}
		System.out.println("NO");
	}

}
